In my experience, the cost of your choking system doesn't have much to do with the density of your pattern. I just did a quick mental recount, and to the best of my memory I've killed turkeys with more than 30 12-gauge shotguns, choked with just about every system known to modern man. And I'd have to say the one that threw the tightest pattern was an old full-choke single-barrel Stevens hammer gun that belonged to my grandfather. It only had a 2-3/4 inch chamber, but that thing threw an absolutely devastating pattern with Winchester Hi-V lead 5s. It wasn't as impressive with Federal or Remington shells (although the pattern with those shells was plenty good enough,) but with the black shells it would just obliterate the 10-inch circle at 40 yards - 150-plus pellets on average.
That's an unusual circumstance, I guess, but there it is anyway. The only reason I'm not still shooting that gun is because it has too much sentimental value to hunt with - and also because my stingy old uncle, who has a generation's better claim to the gun than I do, won't let me.
I guess the point is that there's a lot more than dollars and choke measurement that's involved with creating a consistent, tight pattern: barrel length, barrel smootness, length of the forcing cone, shot size, shell velocity, shell brand, blahblahblahblah. How you hold your mouth when you pull the trigger, for all I know about it. The trick is to try different combinations of all the above variables. find a combination that works for you, and then stick with it and quit trying to perfect the imperfectible.
In the end, every time you pull the trigger of a shotgun you're setting in motion a random, unpredictable act, and the best we can do is try to put together a shotsize-gun-shell brand-choke size-whatver that will minimize that unpredictability.